In laparoscopic surgery, the surgeon performs the operation through one or more small incisions using long instruments, while observing the internal anatomy with an endoscope camera. The laparoscope is often provided with some form of gantry or holding unit to hold the external portion of the device in place. This gantry is often a somewhat cumbersome apparatus and is in general associated with a particular laparoscopic device. Each form of surgical laparoscope will have its own gantry which must be installed before use.
For example U.S. Pat. No. 5,878,193 provides a robotic system that moves a surgical instrument in response to the actuation of a control panel that can be operated by the surgeon. The robotic system has an end effector that is adapted to hold a surgical instrument such as an endoscope. The end effector is coupled to a robotic arm assembly which can move the endoscope relative to the patient. The system includes a computer which controls the movement of the robotic arm in response to input signals received from the control panel. The robotic system is mounted to a cart which can be wheeled to and from an operating table.
An example of laparoscopic surgery is Functional Endoscopic Sinus Surgery (FESS) used to relieve blockages and discomfort in the nasal sinuses—a commonly performed operation.
During laparoscopic surgery it is often required to shift the spatial placement of the endoscope in order to present the surgeon with an optimal view. Conventional laparoscopic surgery makes use either of human assistants who manually shift the instrumentation or alternatively of robotic automated assistants. Automated assistants utilize interfaces that enable the surgeon to direct the mechanical movement of the assistant, achieving a shift in the camera view. U.S. Pat. No. 6,714,841 discloses an automated camera endoscope in which the surgeon is fitted with a head mounted light source that transmits his head movements to a sensor, forming an interface that converts said movements to directions for the mechanical movement of the automated assistant. Alternative automated assistants incorporate a voice operated interface, a directional key interface, or other navigational interfaces. The main disadvantage of the above interfaces is that they are based on cumbersome operations for starting and stopping movement directions that requires the surgeon's constant attention.
Arshak's article “A Model for Estimating the Real Time Positions of a Moving Object in Wireless Telemetry Applications Using RF Sensors” (Arshak, K.; Adepoju, F. Sensors Applications Symp. 2007, 1-6) relates to a method for locating a transmitting object using multiple receiving antenna sensors located at various place surrounding the transmitting device. The receiver antennas are assumed to be omni-directional and the location of the transmitter is achieved through distance estimation (i.e., triangulation) from each of the receiving antennae.
The distance from the transmitter is estimated by measuring the received signal strength (RSS) of the received signal, where the estimated RSS (in dB) is given by the following equation:RSS=PT−PL(d0)−10η log10(d/d0)+Xσwhere PT is the transmitted power, PL(d0) is the path loss for a reference distance d0, η is the pass loss exponent, d is the distance between the transmitter and the receiver, and Xσ is a Gaussian random variable.
Therefore, the signal received is proportional to PT and the ηth power of distance to the transmitter. In free space, η is normally equal to 2. The location of the transmitter can thus be determined by using the above equation to calculate the distance to each of the receiving antennas and triangulating. Arshak states in the article that other methods such as time of arrival, time differences of arrival and angle of arrival are not feasible in dense, multipath environments. If, however, the transmission power is unknown, unstable or inaccurate, or if the propagation factor is unknown, then Arshak's method cannot be used. An efficient method for enabling the relative position of the transmitter (and thus the medical instrument) to be determined therefore remains a long-felt need.
Research has suggested that these systems divert the surgeon's focus from the major task at hand. Therefore technologies based on various kinds of positioning systems have been developed to simplify interfacing control. These technologies still fail to address another complicating interface aspect of laparoscopic surgery, however, as they do not allow the surgeon to signal both to the automated assistant and to surgical colleagues on which surgical instrument his attention is focused.
Hence, a system for laparoscopic surgery providing multiple laparoscopic tools while employing a single external holding device is a long felt need, especially in the field of sinus surgery. Additionally there is a further long-felt need for a device that would allow the surgeon to identify to the laparoscopic computing system as well as to surgical colleagues to which surgical instrument attention is to be directed, thereby directing the view provided by the endoscope to the selected area of interest.